On Wed, Jun 24, 2015 at 01:25:03PM +0300, Kirill A. Shutemov wrote: > With DAX, pfn mapping becoming more common. The patch adjusts GUP code > to cover pfn mapping for cases when we don't need struct page to > proceed. > > To make it possible, let's change follow_page() code to return -EEXIST > error code if proper page table entry exists, but no corresponding > struct page. __get_user_page() would ignore the error code and move to > the next page frame. > > The immediate effect of the change is working MAP_POPULATE and mlock() > on DAX mappings. > > Signed-off-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx> > Reviewed-by: Toshi Kani <toshi.kani@xxxxxx> > Cc: Matthew Wilcox <willy@xxxxxxxxxxxxxxx> Acked-by: Matthew Wilcox <willy@xxxxxxxxxxxxxxx> -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>